Note: Black cohosh (Cimicifuga racemosa) is not to be confused with blue cohosh (Caulophyllum thalictroides) , which contains potentially cardiotoxic or vasoconstrictive chemicals. Black cohosh (Cimicifuga racemosa) is also not to be confused with Cimicifuga foetida, bugbane, fairy candles, or sheng ma; these are species from the same family (Ranunculaceae) with different therapeutic effects.

Black cohosh is popular as an alternative to hormonal therapy in the treatment of menopausal symptoms such as hot flashes, mood disturbances, excessive sweating, palpitations, and vaginal dryness. Several studies have reported black cohosh may improve menopausal symptoms for up to one year, although the evidence is mixed.

The mechanism of action of black cohosh remains unclear. Research suggests that there may be no direct effects on estrogen receptors, although this is an area of active controversy.

Safety and efficacy beyond one year have not been proven. Reports suggest the safety of short-term use, including in women with menopausal symptoms for whom estrogen replacement therapy is not suggested. Nonetheless, caution is advised until better-quality safety data are available. There have been reports of liver damage and higher lead levels in the blood from black cohosh. Use of black cohosh in high-risk populations (such as in women with a history of breast cancer) should be under the supervision of a licensed healthcare professional.

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

GRADE *

A study using black cohosh and other herbs reduced pain. Due to limited research, the effect of black cohosh on arthritis is unclear. Additional studies are needed in this area.

C

Studies show that black cohosh has mixed effects on bone density. More research is needed in this area.

C

Research suggests that black cohosh has mixed results on breast cancer, possibly due to product variability and dosage. Additional studies are needed in this area.

Available research suggests that the effect of black cohosh on infertility is unclear. Additional research is needed in this area.

C

Black cohosh is a popular alternative to prescription hormonal therapy for the treatment of menopausal symptoms. Initial human research suggests that black cohosh may improve some of these symptoms for up to one year. However, the current evidence is mixed, and additional research needed.

C

Black cohosh has not been well studied for mental performance in postmenopausal women. More research is needed in this area.

C

Black cohosh may be a potential treatment for migraines associated with menstruation. Additional research on black cohosh alone is warranted.

C

* Key to grades

A: Strong scientific evidence for this useB: Good scientific evidence for this useC: Unclear scientific evidence for this useD: Fair scientific evidence for this use (it may not work)F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory
The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

There is no proven effective dose for black cohosh. The British Herbal Compendium recommends 40-200 milligrams of dried black cohosh root daily in divided doses, although traditional doses have been as high as one gram three times daily. As a tincture or liquid, the British Herbal Compendium recommends 0.4-2 milliliters of a (1:10) 60% ethanol tincture daily. Powdered black cohosh root or tea (1-2 grams three times daily) also has been used.

For bone density in postmenopausal women, preparations containing 40 milligrams of black cohosh have been taken by mouth for up to three months.

For breast cancer treatment (menopausal symptoms), 1-4 tablets containing 2.5 milligrams of black cohosh extract have been taken by mouth for six months in addition to tamoxifen. In another study, 20 milligrams of black cohosh was taken by mouth daily for a year. A dose of 20 milligrams of black cohosh has also been given twice daily for 1-6 months.

For heart disease in postmenopausal women, 40 milligrams of black cohosh has been taken by mouth daily for three months, stopped for three months, then taken for three months again.

For infertility, 120 milligrams of black cohosh root has been taken by mouth daily for 12-13 days.

For menopausal symptoms, 6.5-160 milligrams of an alcoholic black cohosh extract, a black cohosh root extract, or other black cohosh formulations has been taken by mouth daily for up to one year in various studies. In some studies, 40 drops of a liquid extract have been taken by mouth once or twice daily for up to 24 weeks. An adjusted dose of black cohosh, starting at 64 milligrams for two weeks increased to 128 milligrams by the fourth week, has been studied.

For mental performance in postmenopausal women, 128 milligrams of ground black cohosh parts has been taken once daily by mouth for one year.

Children (under 18 years old)

There is not enough scientific information to recommend black cohosh in children.

Safety
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Avoid with known allergy or sensitivity to black cohosh, its parts, or other members of the Ranunculaceae (buttercup or crowfoot) family.

In nature, black cohosh contains small amounts of salicylic acid (which is found in aspirin), but it is not clear how much (if any) is present in commercially available products. Black cohosh should be used cautiously in people allergic to aspirin or to other salicylates.

A minor allergic skin reaction occurred in one person taking Remixin® (40mg per tablet, Mikro-Gen, Istanbul, Turkey) in a study. Allergic reactions were also reported from a different case study. In another study, allergic eye inflammation occurred in one patient who was given either Remifemin® or Remifemin® Plus.

Side Effects and Warnings

Black cohosh is generally safe in recommended doses and when used up to one year in healthy, nonpregnant, nonbreastfeeding women. Long-term safety data are lacking.

Black cohosh has been well tolerated in breast cancer patients when taken simultaneously with tamoxifen, and in breast cancer survivors with hot flashes.

Black cohosh may cause low blood pressure. Caution is advised in people taking drugs or herbs and supplements that lower blood pressure

Use cautiously in people with a history of hormone-sensitive conditions, such as breast cancer, uterine cancer, or endometriosis (growth of endometrial tissue outside the uterus). Use cautiously in people with known seizure disorders, liver disease, or a history of stroke or disease involving blood clots. Use cautiously as a labor-inducing agent simultaneously with blue cohosh (Caulophyllum thalictroides).

Avoid in pregnant or breastfeeding women.

Avoid in patients with known allergy to black cohosh, its parts, aspirin, other salicylates, or members of the Ranunculaceae (buttercup or crowfoot) family.

Safety during pregnancy and breastfeeding has not been established. Black cohosh may relax the muscular wall of the uterus, and some nurse-midwives in the United States use black cohosh to stimulate labor. There is one report of severe multiorgan damage in a child delivered with the aid of both black cohosh and blue cohosh (Caulophyllum thalictroides) who was not breathing at the time of birth. The child survived with permanent brain damage. However, blue cohosh is known to have effects on the heart and blood vessels and may have been responsible for these effects.

Black cohosh may also have hormonal effects, and caution is advised during breastfeeding. There is a lack of scientific evidence on the use of black cohosh during breastfeeding.

Tinctures may be ill-advised during pregnancy, due to their potentially high alcohol content.

Because black cohosh may contain estrogen-like chemicals, the effects of other agents believed to have estrogen-like properties may be altered. The potential estrogen-like effects of black cohosh remain debated, and the active chemical contents of black cohosh have not been clearly identified. Although recent studies suggest no significant effects of black cohosh on estrogen receptors in the body, caution is warranted in people taking both black cohosh and estrogens, due to unknown effects. The influence of black cohosh in combination with tamoxifen is not clear in studies, and it is not known if tamoxifen counteracts the effects of black cohosh. Drugs like raloxifene may also interact.

Black cohosh may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).

Black cohosh may lower blood pressure and therefore should be used cautiously with other hypotensive agents such as beta-blockers like metoprolol (Lopressor®, Toprol®) or propranolol (Inderal®) and calcium-channel blockers like diltiazem (Cardizem®, Tiazac®) or verapamil (Isoptin®, Calan®). Black cohosh may contain small amounts of salicylic acid and may increase the anti-platelet effects of other agents such as aspirin.

Black cohosh may interfere with the way the body processes certain drugs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may be altered in the blood and change the intended effects. People taking any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.

Many tinctures contain high levels of alcohol and may cause nausea or vomiting when taken with metronidazole (Flagyl®) or disulfiram (Antabuse®).

Interactions with Herbs and Dietary Supplements

Because black cohosh contains estrogen-like chemicals, the effects of other agents believed to have estrogen-like properties may be altered. Black cohosh should be used cautiously in people taking herbs with possible hormonal effects. This is a theoretical concern, and it is not clear if the amounts of salicylates present in commercial or processed black cohosh products have significant effects in humans.

Seizures were reported in a woman taking a combination of black cohosh, chaste-tree (berries and seeds), and evening primrose oil for four months and who also consumed alcohol. The cause of her seizures is not clear.

Both black cohosh and blue cohosh (Caulophyllum thalictroides) are used by nurse-midwives in the United States to assist birth. There is one report of severe multiorgan damage in a child delivered with the aid of both black cohosh and blue cohosh who was not breathing at the time of birth. The child survived with permanent brain damage. However, blue cohosh is known to have effects on the heart and blood vessels and may have been responsible for these effects. Pennyroyal and black cohosh should not be used together, as there is a possibility of increased toxicity and death.

Black cohosh may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.

Black cohosh may lower blood pressure and therefore interact with other herbs or supplements that also affect blood pressure.

Black cohosh may interfere with the way the body processes certain herbs or supplements using the liver's cytochrome P450 enzyme system. As a result, the levels of other herbs or supplements may become changed in the blood. It may also alter the effects that other herbs or supplements possibly have on the P450 system.

Black cohosh may potentially interact with American pennyroyal; antihistamines; antioxidants; blue cohosh (Caulophyllum thalictroides); chasteberry; cholesterol lowering herbs and supplements; evening primrose oil; herbs and supplements for arthritis, cancer, or osteoporosis; herbs and supplements for depression or selective serotonin reuptake inhibitors (SSRIs); herbs and supplements for inflammation, pain relief or sensation loss; herbs and supplements for the brain, intestines or stomach; herbs and supplements taken by mouth; herbs and supplements that alter the effect of dopamine; herbs and supplements that inhibit blood clots and platelet aggregation; herbs and supplements that may lower seizure threshold; herbs and supplements that prevent androgen expression; herbs and supplements that widen blood vessels; herbs and supplements toxic to the liver; hormonal herbs and supplements; hormone replacement therapy herbs and supplements; salicylate-containing herbs and supplements (e.g., willowbark); and St. John's wort.

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.